40656521 has 4 divisors (see below), whose sum is σ = 42058500. Its totient is φ = 39254544.

The previous prime is 40656491. The next prime is 40656541. The reversal of 40656521 is 12565604.

40656521 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 18800896 + 21855625 = 4336^2 + 4675^2 .

It is a cyclic number.

It is not a de Polignac number, because 40656521 - 2¹⁴ = 40640137 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (29), and also a Moran number because the ratio is a prime number: 1401949 = 40656521 / (4 + 0 + 6 + 5 + 6 + 5 + 2 + 1).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (40656541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 700946 + ... + 701003.

It is an arithmetic number, because the mean of its divisors is an integer number (10514625).

Almost surely, 2^40656521 is an apocalyptic number.

It is an amenable number.

40656521 is a deficient number, since it is larger than the sum of its proper divisors (1401979).

40656521 is a wasteful number, since it uses less digits than its factorization.

40656521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1401978.

The product of its (nonzero) digits is 7200, while the sum is 29.

The square root of 40656521 is about 6376.2466232102. The cubic root of 40656521 is about 343.8561036208.

The spelling of 40656521 in words is "forty million, six hundred fifty-six thousand, five hundred twenty-one".